crinum overwintering questions

I am from Ohio, (but in MD for 7 years now) where Crinums were container-only plants. I have grown the related Lycoris, but only the x squamigera.

I want to try some more this year.

Questions:

1. Crinums are mostly said to be "evergreen" in winter, not dying back on their own accord. In a zone 7a winter like the one we just had (are still having...really) when we have multiple lows of zero to the mid single digits, some with snowcover, and some without...I assume there will be total or considerable foliage dieback. Does that affect the bloom for that season when that happens? Or is it a typical occurence they just laugh off?

2. Same question for the so-called "winter foliage" Lycoris species - x squamigera foliage emerges in spring, whereas some, like radiata, are said emerge in fall and stay through winter.

3. I've even seen some crinums rated to zone 6 - of interest since I have family in Ohio - is that pushing it?

1. I live in zone 8a, changed from 7b last year. I have grown crinums for about l0 years. I have never seen any of them stay green over winter. I give them a top dressing of manure each fall and then mulch them well with pine straw. I do not cut them back. The foliage freezes into a black, stringy goo. I leave it right where it is. I believe it insulates the bulbs, whose necks are above ground. In spring, when I see them trying to emerge, THEN I go out and pull all the debris from the previous year off. It will actually be attached to the beginnings of this years' leaves, but is easy to remove. This winter die back has never caused mine to fail to bloom. (I have about 6 to l0 varieties, I guess.)

2. I have lots of Lycoris radiata bulbs and a new this year planting of squamigera. We have had the coldest winter I have experienced here in the sense that we have had very long terms of very cold weather. But still, our coldest temp this year was 9 and that was only for a couple hours on one day. I have seen zero once in 25 years here. All that being said, lycoris foliage is evergreen here every year I have gardened. I have never seen it so much as freeze burn. Radiata blooms in fall here, with foliage following a couple weeks later. It stands all winter and goes dormant with the daffodils. This is my first year for squamigera. I only got the bulbs a few weeks ago from a friend. The foliage was partially emerged when she gave them to me. It is beautiful and healthy right now.

This year (zone 6 here), I lost the radiata foliage in December, which wasn't long after they emerged...due to the incredibly harsh winter we had. I'm sure my radiata won't be blooming for a couple years. This has been not the norm....
I have a crinum x powellii (one of the hardiest), and after several years to get the first bulb to maturity, it flowered at least once a year after that. And yes, the foliage has pretty much no frost tolerance....it's gonna go black and slimy easy/early and die back.

I've solved the problem, or at least tried to avoid it, by planting these two in containers. I took them to my crawlspace, when the low temps were in the low 20s and below. both have stayed green; they're currently outside, but with 'another system' coming in overnight, they'll be inside for the next two nights. The pink xpowellii needs potting up, since it has a more recently acquired alba version with it, and is potbound. None have matured and bloomed yet.

I planted quite deep (knowing I didn't want the bulb to freeze) originally. I believe crinums tend to self-adjust on depth (not sure on that). I mulched pretty heavily the first 2 or 3 years.
I had perhaps 5 bulbs with growing points above ground after 7-10 years....not fast multiplication by any means.